Fuel Pump Voltage Regulator Bybass

[Dan_J]

so on a rb20 cefiro, walbro pump, stock injectors, ecu, afm, i had to wire the fuel pump relay trigger wire to ignition and bypass the factory voltage regulator due to an electrical fault.

car isnt a daily and hasnt been in use due to an electrical problem which was put on the back burner until recent. swapped out spark plugs for new ones as they were fouled up, plugs still seem to be fouling up, stalling on idle randomly after some time, bit of throttle keeps it from stalling as i figure more air = better mixture, less fuel. also car is quite laggy than usual as i figure fouling plugs, too rich and bad spark is the

only real change is the voltage regulator bypass, other than the past electrical issue, so to rule one thing out i wonder who has bypassed the regulator and had problems etc as described ?

thanks

Edited November 14, 2015 by Dan_J

[scotty nm35]

Have you had a fuel pressure gauge on it? Some cars have a restrictor in the return line for some reason...

[Dan_J]

i've read that one thread, quite a weird one there, although im not running a huge 400/450 lph walbro. I'll put a pressure gauge on to rule it out

[Dan_J]

so its not fuel pressure, 43-45 psi on idle 50 psi on revs/ regulator vacuum hose unplugged .

can injectors leak on the inside, say kinda stuck half open when they're ment to be closed? as when i put stock injectors back in they got mixed with a spare set

will also try a another stock ecu soon

[XKLABA]

Has it been tuned for the walbro, when I fitted one to my 32 it went rich as fark

Also I'm not sure about the Cefiro but on the 32 the voltage reg is on the negative/earth side of the pump

It is possible for injectors to to all sorts of crasy shit including not shutting properly so maybe a clean and flow check might be in order

[Dan_J]

Has it been tuned for the walbro, when I fitted one to my 32 it went rich as fark

Also I'm not sure about the Cefiro but on the 32 the voltage reg is on the negative/earth side of the pump

It is possible for injectors to to all sorts of crasy shit including not shutting properly so maybe a clean and flow check might be in order

well it run, boosted and skidded fine on the walbro for quite awhile before electrical issue, now crazy laggy barely making boost, fouling plugs, stalling etc

does anyone even know what the regulator looks like? i'm not sure, may even be one in the ecu

i'll give the injectors a test with water and a 12v pump to see if they seal/ close fully

[scotty nm35]

Test them with water and you may need to replace the whole set. Don't ever test fuel system parts with water, especially pumps and injectors.

Have you pressure tested your intake?

[Dan_J]

thought that was just if you ran water in injectors for a while it would rust up, not just for a lil test, and with a water/ liquid pump not fuel pump but fair enough

yep pressure tested the intake with the plastic end cap and tyre valve method, no real leaks, holds pressure fine